code: def test_mean_reciprocal_rank():
      label = [0, 1, 2]
      score = [0.1, 0.4, 0.2]
      assert metrics.MeanReciprocalRank()(label, score) == 1
  
file_path: MatchZoo/tests/unit_test/test_metrics.py
imports: import numpy
  from matchzoo.engine.base_metric import sort_and_couple
  from matchzoo import metrics
label_desc: Use image node_id 2 for calling a global function with example usage: test_mean_reciprocal_rank() without return types